Drying apparatus



Nov. 30 1926.

H. HAAS DRYING APPARATUS Filed Dec. 2, 1925 Fig.1. 6

lnvenTor. Hermann Hons Anya.

Patented Nov. 30, 19126.

' UNITED" STATES PATENT OFF-1cm anama ms; or murmur, onnirm.

DRYING APPARATUS.

' Application filed December- 2, 1925, Serial No. 72,715, and in Germany December 4, 182$.

- This inventioni'elates to drying apparatus of that type whichcomprises a plurality of drying chambers and a plurality of heat in cambers arranged alternately so that a rying current may be assed throughthe chambers successively. n rior drying apparatus of thist e it has canthe com: mon practice to emp 0y a single'zrir-forcing mechanism usually"in the form of an exhauster or suction apparatus which operates to drawthe dryin current through the series of chambers, t e drying currentbeing drawn into' a heating chamber ;where it is heated and then passingto the adjacent is drying chamber where it performs its drying functionand then passing into the next heat-- ingchamber where it is reheatedfrom which it passes to another drying chamber and so on. o

This arrangement has the disadvantage that since the single suctionapparatus or exhauster is required to draw the'air current through allthe chambers successively it is necessary to operate the exhauster withak a drying apparatus of the above type which has alternately arrangedheating and drying chambers by providing a construction by which therequired movement of air will be secured through the chambers to efiectthe necessaryldrymg with a considerably reduced power consumption. Inorder to give an understanding of the invention I have illustrated inthe drawings a selected embodiment thereof which will now be describedafter which the novelv features. willbe pointedout in the appended iclaims Fig. 1 of the drawings'is a sectional view illustrating anapparatus of the type which has heretofore beenus'ed;

Fig. 2 is a similar view illustrating an apparatus embodying myinvention; Fig. 3 is a section on the line 3-3, Fig. 2; Referringfirstfto Fig. 1,1, 2, and 3 inconsiderable vacuum in order to overcomethe resistance which the air meets 111 passing dicate-dryingchambers and4, 5, and 6 indicate heatlng chambers, said heating chambers having somesuitable heating means ing chamber 1 communicates with the upper end oftheheating, chamber 5 throu h an opening 10 and said heating cham er 5communicates at its lower end with the drymg chamber 2through an opening11. The

drying chamber 2 also has communication w1th the heating chamber 6through :3 an

opening 12 and said heating cham communicates at its lower end with thedrying chamber 3 through the opening 13.

14 indicates 'a suction or exhaustapparatus, theinlet of which hascommunication with a pipe 15, the latter having ports or openings 16leading to the various drying chambers. Each opening is provided with aclosure 17 by which it may be closed as shown in Fig. 1. The closure 17for the opening 16 leading to the last drying chamber 3 is open, theother closures being closed and with this arrangement the eithauster 4will draw air in through the open? ing 8- and pass itsuccessivelythrough the heating an by the line of arrows 18. \Vith thisarrangement the suction "apparatus has to develop sufiicient suction orvacuum to overcome the combined resistance in all of the chambers,

The improvements constituting the pres- 'ent invention consist ofemploylng a pludrying chambers asindicated rality of blowers, one foreach drying,

chamber, each .blower being arranged to cause a local circulationthrough each drying chamber and the corresponding heating chamber andalso tocause a progressive movement of the air through the dryingchambers and heating chambers.

In Fig. 2, which illustrates my improvement, 19, 20 and 21 indicatedrying chambers and 22, 23 and '24 indicate the corresponding heatingchambers, each heating chamber having the heatingpipes 25 there in. Eachheating chamber communicates With its corresponding drying chamber atboth the top and the bottom and also communicates with the next adjacentdrying chamben- For instance, the heating chamber 24 communicates withits drying chamber 21 through the top opening 32 and the bottom opening31 and communicates with the adjacent drying chamber 20 through theopening 33. The heating chamber 223 communicates with its drying chamber20 through the top opening 29 and the bottom opening 28 and alsocommunicates with the adjacent drying chamber 19 through the opening 39.The heating chamber conununicates with its drying chamber 19 through thetop opening 27 and bottom opening 26 and also communicates with thedrying'chamber 21 through a passage or conduit 44 one end of saidpassage communicating with the upper end of the heating chamber 22 andthe other end of the passage communicating with the chamber 21 throughthe opening 49.

Each drying chamber has an inlet open ing 39 leading thereto and aclosure 40 for this opening. These closures may be independently openedso that the different inlet openings 39 may be selectively opened orclosed. Each drying chamber also has an outlet or discharge opening 41leading to a conduit42 which communicates with the atmosphere and eachdischarge opening 41 has a closure 43 by which it may be opened orclosed. The closures 43 are capable of independent operation and thusthe heating chambers may be selectively connected to thethe same shaft37 which may be driven in any suitable way as by means of a drivingpulley 38.

In the operation of the device the exhaust opening 41 of the heatingchamber which corresponds to the drying chamber having the wettestmaterial therein will be opened, the exhaust openings 41 of the otherdrying chambers being closed. and the inlet opening 39 of the dryingchamber having the dryest material therein will be opened, the otherinlet openings being closed. As shown in Fig. 2 it is assumed that thedrying chamber 19 has the wettest material therein and the dryingchamber 21 the dryest.

lVhen the shaft 37 is rotated and the windwheels or air-forcing devices34, 35

ing downwardly through the heating chamber and then into the lower endof the corresponding drying chamber and thence back into the heatingchamber again'where it passes downwardly. In addition to these localcurrents there will be a gradual or progressive movement of the airthrough the chambers successively as indicated by the full lines, theair entering continuously through the open inlet port 39 (this portbeing the inlet port leading to the chamber having the dryest materialtherein) and passing progressively through the drying and heatingchamberssuccessively to the open discharge port 41 (which will be thedischarge port of the chamber having the wettest material therein).Hence with this arrangement there will be a local circulation througheach heating chamber and its drying chamber and a progressive movementof the air from the chamber having the dryest material to the chamberhaving the wettest material therein.

When the material in the chamber-21 is thoroughly dried it may beremoved and the chamber filled with wet material which is to be dried.When this is done the chamber 20 will then have the dryest materialtherein and the chamber 21 the wettest material and to ctntinue thedrying operation the inlet portion 39 leading to the chamber 21 will beclosed while the inlet port leading to the chamber 20 will be opened.Similarly, the discharge port 41 leading from the heating chamber 22will be closed and that leading from the heating chamber 24 will beopened. When this is done then the air will be entering continuouslythrough the inlet port into the chamber 20 which now contains the dryestmaterial and will pass progressively through the heating chamber 23through the drying chamber 19 and through the conduit 44 into the dryingchamber 21 which contains the wettest material from which it will bedischarged.

Vhen the material in the chamber 20 becomes thoroughly dried it may beremoved and the chamber filled with wet material at which time thechamber 19 will contain the dryest material and the chamber 20 thewettest material. leading to the chamber 20 is then closed and thatleading to the cha1nber'19 is opened while the discharge opening 41leading from the chamber 21 is closed and that leading from the chamber20 is opened. Upon continued operation there will be not only the localcirculation set up as heretofore de scribed but a continuous progressivecirculation through the chambers beginning with the chamber 19 havingthedryest material therein and ending with the chamber. 20 having thewettest material therein. The chambers may thus be emptied and filledprogressively as the drying proceeds and at The inlet valve 39 all timesthere will be both a local circulation indicated by the dotted lines andthe progressive circulation through the series of chambers, whichprogressive circulation always starts with the chamber having the dryestmaterial therein, and ends with the chamber having the wettest materialtherein.

Another advantage gained from this structure is that each windwheel hasto overcome only the resistance of its local circulation and, therefore,it will not be necessary for the windwheels to operate under such highvacuum as would be the case in the construction shown in Fig. 1. Theapparatus shown in Fig. 2, therefore, can be operated with a much lessconsumption of power than one such as shown in Fig. 1. Practical testsin dryers have shown that of two dryers of the same size, oneconstructed as shown in Fig. 1 andthe other as shown in Fig. 2, a dryeras illustrated in Fig. 2 will require only about one-half'the power thatis required to operate the dryer constructed in Fig. 1.

I claim:

1. A drying apparatus comprising a plurality of drying chambers, aheating chamher for each drying chamber, each heating chambercommunicating with its drying chamber at both the top and the bottom andalso communicating with an adjacent drying chamber, a blower for eachdrying chamber by which a local circulation is established through saiddrying chamber and corresponding heating chamber, each of the dryingchambers having an inlet opening, and an outlet or discharge opening,and closures by which said openings may be independently opened orclosed, whereby in addition to said local circulation there will be aprogressive displacement of air from the open inet through the connectedchambers to the open outlet.

2. A drying apparatus comprising a plurality of heating ehambers eachhaving an inlet and an outlet with closures for the inlets and outletswhich may be independently opened or closed and by means of which theinlet of any heating chamber and the dis- .charge from an ad acentheating chamber may be opened, a drying chamber for each heatingchamber, and means to establish a local circulation of air through eachdrying chamber and its corresponding heating chamber and aso to producea progressive displacement of air from the open inlet through the dryingchambers and heating chambers in succession to the open outlet.

In testimony whereof, I have signed my name to this specification.

HERMANN HAAS.

